Binge eating is a prevalent problem among obese individuals. Obese binge eaters meet DSM-III criteria for bulimia and report disturbed eating behaviors, maladaptive cognitions about diet and weight, and marked dysphoria. To date these patients have been treated primarily in weight control programs, but unfortunately these programs fail to modify binge behaviors or to produce long-term changes in weight. The proposed project represents one of the first efforts to develop a treatment program specifically for obese binge eaters. The goals of this treatment program are to ameliorate the eating disorder and reduce body weight. The specific aim of the project is to test the effectiveness of a cognitive behavioral treatment that has been used successfully with normal weight bulimia nervosa patients in the treatment of obese binge eaters. One hundred and eight obese women who meet DSM-III-R criteria for bulimia will be randomly assigned to either cognitive behavioral treatment for bulimia (BULIMIA), behavioral weight control (WEIGHT) or a delayed treatment control. The treatment programs will consist of 22 individual therapy sessions over a 6 month period followed by 6 maintenance sessions. Patients in the three conditions will be interviewed before and after the 6 month treatment interval to assess changes in binge behaviors, weight, cognitions about weight and shape, and mood. The delayed treatment condition will then receive the program that appears most effective. Patients in the other conditions will be reassessed after 6 and 12 months to compare the long-term effectiveness of the progams. This project will provide information about the course of bulimia in obese women, the short- and long-term effects of two different treatments on the behavioral, cognitive, and affective components of bulimia, and the role of binge eating in the maintenance of obesity.